1. Field of the Invention
The present invention relates generally to a microstrip antenna for use on a projectile, such as a missile. More particularly, the present invention relates to a ten inch diameter microstrip antenna which has a operating frequency of 425 megahertz.
2. Description of the Prior Art
There is currently a requirement for a microstrip antenna which produces a quasi omni-directional radiation pattern with linear polarization. The microstrip antenna must be a conformal 270 degree wrap around antenna with a ten inch maximum diameter and a five inch maximum length. The antenna's required frequency of operation is 425 MHz ±375 KHx. For reliability purposes, two outputs from the microstrip antenna are required with integrated power division. The antenna is to be used as a flight termination system (FTS) antenna.
Generally, a microstrip antenna operates by resonating at a frequency. The conventional design for microstrip antennas uses printed circuit board techniques which include putting a printed copper patch on the top of a layer of dielectric and a copper ground plane on the underside of the dielectric. The frequency of operation of the conventional microstrip antenna is for the length of the antenna to be a half-wavelength in the microstrip medium of dielectric below the patch and air above the patch. A quarter-wavelength microstrip antenna is similar to the half wavelength microstrip antenna except the resonant length is a quarter-wavelength and one side of the antenna is grounded.
Presently, there is no known microstrip antenna which meets the dimensions and frequency requirements set forth for this particular flight termination system antenna.